The small molecule H89 inhibits Chlamydia inclusion growth and production of infectious progeny

Chlamydia is an obligate intracellular bacterium and the most common reportable cause of human infection in the U.S. This pathogen proliferates inside a eukaryotic host cell, where it resides within a membrane-bound compartment called the chlamydial inclusion. It has an unusual developmental cycle, marked by conversion between a replicating form, the reticulate body (RB), and an infectious form, the elementary body (EB). We found that the small molecule H89 slowed inclusion growth and decreased overall RB replication by 2-fold, but caused a 25-fold reduction in infectious EBs. This disproportionate effect on EB production was mainly due to a defect in RB-to-EB conversion and not to the induction of chlamydial persistence, which is an altered growth state. Although H89 is a known inhibitor of specific protein kinases and vesicular transport to and from the Golgi, it did not cause these anti-chlamydial effects by blocking the protein kinases PKA or PKC, or by inhibiting protein or lipid transport. H89 is thus a novel anti-chlamydial compound that has a unique combination of effects on the intracellular Chlamydia infection.

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Biology and intracellular life of chlamydia

Medicinski pregled ◽

10.2298/mpns1112561v ◽

2011 ◽

Vol 64 (11-12) ◽

pp. 561-564 ◽

Cited By ~ 1

Author(s):

Maja Vivoda ◽

Ivana Cirkovic ◽

Djordje Aleksic ◽

Lazar Ranin ◽

Slobodanka Djukic

Keyword(s):

Host Cell ◽

Active Form ◽

Developmental Cycle ◽

Elementary Body ◽

Reticulate Body ◽

Long Time ◽

Developmental Form ◽

Obligate Intracellular Bacteria ◽

Infectious Form

Introduction. Chlamydiae are Gram-negative obligate intracellular bacteria. The developmental cycle of Chlamydiae is specific and different from other bacteria. The elementary body is the infectious form of the organism, responsible for attaching to the target host cell and promoting its entry. The reticulate body is the larger, metabolically active form of the organism, synthesizing deoxyribonucleic acid, ribonucleic acid and proteins. The elementary body and reticulate body represent evolutionary adaptations to extracellular and intracellular environments. Intracellular persistence of Chlamydia. Predisposition of Chlamydia to persist within the host cell has been recognized as a major factor in the pathogenesis of chlamydial disease. The persistence implies a long-term association between chlamydiae and their host cell that may not manifest as clinically recognizable disease. The ability of chlamydia to remain within one morphological state for a long time in response to exogenous factors suggests an innate ability of these organisms to persist intracellulary in a unique developmental form. Chlamydiae induce interferon ? and exhibit growth inhibition in their presence. While the high levels of interferon ? completely restrict the development of chlamydia, its low levels induce the development of morphologically aberrant intracellular forms. The persistent forms contain reduced levels of major outer membrane protein but high levels of chlamydial heat shock protein. Conclusion. Immunopathogenesis of chlamydial infection is one of the main focal points of current research into Chlamydia. Chlamydial infections are highly prevalent, usually asymptomatic and associated with serious sequelae. Screening programmes are the most important in the prevention of a long-term sequele.

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Partitioning of cancer therapeutics in nuclear condensates.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.3131 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 3131-3131

Author(s):

Isaac Klein ◽

Ann Boija ◽

Lena Afeyan ◽

Susana Hawken ◽

Mengyang Fan ◽

...

Keyword(s):

Physicochemical Properties ◽

Small Molecule ◽

Cancer Therapeutics ◽

Therapeutic Index ◽

Regulatory Elements ◽

Specific Protein ◽

Target Engagement ◽

Membrane Bound ◽

In Cells

3131 Background: The molecules of the cell are compartmentalized into membrane- and non-membrane-bound organelles. Many non-membrane-bound organelles are phase-separated biomolecular condensates with distinct physicochemical properties that can absorb and concentrate specific proteins and nucleic acids involved in discrete biochemical processes. We reasoned that selective condensate partitioning might also occur with small molecule drugs whose targets occur within condensates, and that the therapeutic index and efficacy of such compounds might therefore relate to their ability to partition into condensates. Methods: To study the behavior of drugs within condensates, these were modeled in cells and in vitro with purified proteins and visualized by fluorescent confocal microscopy. The functional outcomes of condensate partitioning were queried in cells. Results: We found that cisplatin, tamoxifen, JQ1, THZ1, and mitoxantrone are concentrated in specific protein condensates in vitro, and that this occurs through physicochemical properties independent of the drug target. A screen of a chemically diverse fluorescent probes and mutant-protein condensates demonstrated that pi-system interactions between aromatic moieties in the protein and small molecule govern concentration in condensates. These results show that clinically important drugs partition into specific protein condensates in vitro by virtue of defined chemical properties, thereby altering their local concentration. In vitro droplet assays revealed that cisplatin is selectively concentrated in transcriptional condensates, and that this ability is required for efficient platination of target DNA. In cell studies revealed that cisplatin preferentially targets DNA contained within MED1 condensates, and disrupts the genetic regulatory elements that compose phase-separated transcriptional condensates. Live cell imaging demonstrated that transcriptional condensates are dissolved by cisplatin, whereas other condensates remain intact. Conclusions: Our results show that antineoplastic drugs partition selectively into biomolecular condensates, that this can occur through physicochemical properties independent of their molecular targets, and that drug activity may occur through condensate-related mechanisms. These results have implications for development of efficacious cancer therapeutics; effective target engagement will depend on factors such as drug partitioning in condensates. Assays of the type described here may thus help optimize condensate partitioning, target engagement, and the therapeutic index of drugs for cancer treatment.

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Study of Inhibitors of Neu and Related Tyrosine-Specific Protein Kinases: Implications for the Treatment of Breast Cancer.

10.21236/ada360940 ◽

1998 ◽

Author(s):

Arthur Edelman

Keyword(s):

Breast Cancer ◽

Protein Kinases ◽

Specific Protein

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Substrate specificities of tyrosine-specific protein kinases toward cytoskeletal proteins in vitro.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)66942-x ◽

1986 ◽

Vol 261 (31) ◽

pp. 14797-14803 ◽

Cited By ~ 5

Author(s):

T Akiyama ◽

T Kadowaki ◽

E Nishida ◽

T Kadooka ◽

H Ogawara ◽

...

Keyword(s):

Protein Kinases ◽

Specific Protein ◽

Cytoskeletal Proteins ◽

Substrate Specificities

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Regulation of the cystic fibrosis transmembrane conductance regulator Cl- channel by specific protein kinases and protein phosphatases.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)53959-4 ◽

1993 ◽

Vol 268 (3) ◽

pp. 2037-2047 ◽

Cited By ~ 2

Author(s):

H.A. Berger ◽

S.M. Travis ◽

M.J. Welsh

Keyword(s):

Cystic Fibrosis ◽

Protein Kinases ◽

Protein Phosphatases ◽

Specific Protein ◽

Transmembrane Conductance Regulator ◽

Transmembrane Conductance ◽

Cl Channel ◽

Cystic Fibrosis Transmembrane

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Characterization of an activated human ros gene.

Molecular and Cellular Biology ◽

10.1128/mcb.6.9.3109 ◽

1986 ◽

Vol 6 (9) ◽

pp. 3109-3116 ◽

Cited By ~ 61

Author(s):

C Birchmeier ◽

D Birnbaum ◽

G Waitches ◽

O Fasano ◽

M Wigler

Keyword(s):

Gene Transfer ◽

Protein Kinases ◽

Transmembrane Domain ◽

Extracellular Domain ◽

Kinase Domain ◽

Specific Protein ◽

Normal Human

A human oncogene, mcf3, previously detected by a combination of DNA-mediated gene transfer and a tumorigenicity assay, derives from a human homology of the avian v-ros oncogene. Both v-ros and mcf3 can encode a protein with homology to tyrosine-specific protein kinases, and both mcf3 and v-ros encode a potential transmembrane domain N terminal to the kinase domain. mcf3 probably arose during gene transfer from a normal human ros gene by the loss of a putative extracellular domain. There do not appear to be any other gross rearrangements in the structure of mcf3.

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Effects ofMentha suaveolensEssential Oil onChlamydia trachomatis

BioMed Research International ◽

10.1155/2015/508071 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 9

Author(s):

Rosa Sessa ◽

Marisa Di Pietro ◽

Fiorenzo De Santis ◽

Simone Filardo ◽

Rino Ragno ◽

...

Keyword(s):

Chlamydia Trachomatis ◽

Substantial Reduction ◽

Developmental Cycle ◽

Elementary Body ◽

Promising Candidate ◽

Common Cause ◽

Sexually Transmitted ◽

Reticulate Body ◽

Preventative Strategy

Chlamydia trachomatis, the most common cause of sexually transmitted bacterial infection worldwide, has a unique biphasic developmental cycle alternating between the infectious elementary body and the replicative reticulate body.C. trachomatisis responsible for severe reproductive complications including pelvic inflammatory disease, ectopic pregnancy, and obstructive infertility. The aim of our study was to evaluate whetherMentha suaveolensessential oil (EOMS) can be considered as a promising candidate for preventingC. trachomatisinfection. Specifically, we investigated thein vitroeffects of EOMS towardsC. trachomatisanalysing the different phases of chlamydial developmental cycle. Our results demonstrated that EOMS was effective towardsC. trachomatis, whereby it not only inactivated infectious elementary bodies but also inhibited chlamydial replication. Our study also revealed the effectiveness of EOMS, in combination with erythromycin, towardsC. trachomatiswith a substantial reduction in the minimum effect dose of antibiotic. In conclusion, EOMS treatment may represent a preventative strategy since it may reduceC. trachomatistransmission in the population and, thereby, reduce the number of new chlamydial infections and risk of developing of severe sequelae.

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Tyrosine Specific Protein Kinases in Plant Tissues

Molecular and Cellular Aspects of Calcium in Plant Development ◽

10.1007/978-1-4613-2177-4_50 ◽

1986 ◽

pp. 339-340

Author(s):

D. Blowers ◽

A. J. Trewavas

Keyword(s):

Protein Kinases ◽

Specific Protein ◽

Plant Tissues

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Chlamydial infection and disease in the koala

Microbiology Australia ◽

10.1071/ma05065 ◽

2005 ◽

Vol 26 (2) ◽

pp. 65 ◽

Cited By ~ 3

Author(s):

Peter Timms

Keyword(s):

Chlamydia Trachomatis ◽

Chlamydial Infection ◽

Developmental Cycle ◽

Elementary Body ◽

Obligate Intracellular ◽

Molecular Approaches ◽

Reticulate Body ◽

Wide Range ◽

The Family ◽

Serious Disease

Chlamydiae are obligate intracellular bacterial pathogens able to infect and cause serious disease in humans, birds and a remarkably wide range of warm and cold-blooded animals. The family Chlamydiaciae have traditionally been defined by their unique biphasic developmental cycle, involving the interconversion between an extracellular survival form, the elementary body and an intracellular replicative form, the reticulate body. However, as with many other bacteria, molecular approaches including 16SrRNA sequence are becoming the standard of choice. As a consequence, the chlamydiae are in a taxonomic state of flux. Prior to 1999, the family Chlamydiaceae consisted of one genus, Chlamydia, and four species, Chlamydia trachomatis, C. psittaci, C. pecorum and C. pneumoniae. In 1999, Everett et al proposed a reclassification of Chlamydia into two genera (Chlamydia and Chlamydophila) and nine species (Chlamydia trachomatis, C. suis, and C. muridarum and Chlamydophila psittaci, C. pneumoniae, C. felis, C. pecorum, C. abortus, and C. caviae). While some of these species are thought to be host specific (C. suis ? pigs, C. muridarum ? mice, C. felis ? cats, C. caviae ? guinea pigs) many are known to infect and cause disease in a wide range of hosts.

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